#字符串的使用
# a = 15
# b = 12345678.1234567
# s = 'l love python!'
# print('a = %05d' % a)
# print('b = %8.3f' % b)
# print('%17s' % s)
# print('%-17.6s' % s)

# #分割字符串
# strs = 'This is an EXAMPLE'
# print(strs.lower())
# print(strs.upper())

#连接字符串
# strs = 'Rain  falls       on  field    and       tree'
# print(strs)
# split_strs = strs.split()
# print(split_strs)
# join_strs ='  '.join(split_strs)
# print(join_strs)
